How to use

findAvailableUdpPort

method

in

org.springframework.util.SocketUtils

/**
 * Find an available UDP port randomly selected from the range
 * [{@code minPort}, {@value #PORT_RANGE_MAX}].
 * @param minPort the minimum port number
 * @return an available UDP port number
 * @throws IllegalStateException if no available port could be found
 */
public static int findAvailableUdpPort(int minPort) {
  return findAvailableUdpPort(minPort, PORT_RANGE_MAX);
}

/**
 * Find an available UDP port randomly selected from the range
 * [{@value #PORT_RANGE_MIN}, {@value #PORT_RANGE_MAX}].
 * @return an available UDP port number
 * @throws IllegalStateException if no available port could be found
 */
public static int findAvailableUdpPort() {
  return findAvailableUdpPort(PORT_RANGE_MIN);
}

/**
 * Find an available UDP port randomly selected from the range
 * [{@value #PORT_RANGE_MIN}, {@value #PORT_RANGE_MAX}].
 * @return an available UDP port number
 * @throws IllegalStateException if no available port could be found
 */
public static int findAvailableUdpPort() {
  return findAvailableUdpPort(PORT_RANGE_MIN);
}

/**
 * Find an available UDP port randomly selected from the range
 * [{@code minPort}, {@value #PORT_RANGE_MAX}].
 * @param minPort the minimum port number
 * @return an available UDP port number
 * @throws IllegalStateException if no available port could be found
 */
public static int findAvailableUdpPort(int minPort) {
  return findAvailableUdpPort(minPort, PORT_RANGE_MAX);
}

@Test
public void findAvailableUdpPortWithNegativeMinPort() {
  exception.expect(IllegalArgumentException.class);
  SocketUtils.findAvailableUdpPort(-500);
}

@Test
public void findAvailableUdpPortWithZeroMinPort() {
  exception.expect(IllegalArgumentException.class);
  SocketUtils.findAvailableUdpPort(0);
}

@Test
public void findAvailableUdpPort() {
  int port = SocketUtils.findAvailableUdpPort();
  assertPortInRange(port, PORT_RANGE_MIN, PORT_RANGE_MAX);
}

@Test
public void findAvailableUdpPortWithMin() {
  int port = SocketUtils.findAvailableUdpPort(50000);
  assertPortInRange(port, 50000, PORT_RANGE_MAX);
}

@Test
public void findAvailableUdpPortInRange() {
  int minPort = 20000;
  int maxPort = minPort + 1000;
  int port = SocketUtils.findAvailableUdpPort(minPort, maxPort);
  assertPortInRange(port, minPort, maxPort);
}

@Test
public void findAvailableUdpPortWhenPortOnLoopbackInterfaceIsNotAvailable() throws Exception {
  int port = SocketUtils.findAvailableUdpPort();
  DatagramSocket socket = new DatagramSocket(port, InetAddress.getByName("localhost"));
  try {
    exception.expect(IllegalStateException.class);
    exception.expectMessage(startsWith("Could not find an available UDP port"));
    exception.expectMessage(endsWith("after 1 attempts"));
    // will only look for the exact port
    SocketUtils.findAvailableUdpPort(port, port);
  }
  finally {
    socket.close();
  }
}

/**
 * Find an available UDP port randomly selected from the range
 * [{@value #PORT_RANGE_MIN}, {@value #PORT_RANGE_MAX}].
 * @return an available UDP port number
 * @throws IllegalStateException if no available port could be found
 */
public static int findAvailableUdpPort() {
  return findAvailableUdpPort(PORT_RANGE_MIN);
}

/**
 * Find an available UDP port randomly selected from the range
 * [{@code minPort}, {@value #PORT_RANGE_MAX}].
 * @param minPort the minimum port number
 * @return an available UDP port number
 * @throws IllegalStateException if no available port could be found
 */
public static int findAvailableUdpPort(int minPort) {
  return findAvailableUdpPort(minPort, PORT_RANGE_MAX);
}

/**
 * Find an available UDP port randomly selected from the range
 * [{@value #PORT_RANGE_MIN}, {@value #PORT_RANGE_MAX}].
 * @return an available UDP port number
 * @throws IllegalStateException if no available port could be found
 */
public static int findAvailableUdpPort() {
  return findAvailableUdpPort(PORT_RANGE_MIN);
}

/**
 * Find an available UDP port randomly selected from the range
 * [{@code minPort}, {@value #PORT_RANGE_MAX}].
 * @param minPort the minimum port number
 * @return an available UDP port number
 * @throws IllegalStateException if no available port could be found
 */
public static int findAvailableUdpPort(int minPort) {
  return findAvailableUdpPort(minPort, PORT_RANGE_MAX);
}

private static int findAvailableUDPPort() {
  return SocketUtils.findAvailableUdpPort(minPort, maxPort);
}

@Autowired
public AbstractUdpReceiverPublisher(OdeProperties odeProps, int port, int bufferSize) {
 this.odeProperties = odeProps;
 this.port = port;
 this.bufferSize = bufferSize;
 try {
   socket = new DatagramSocket(this.port);
   logger.info("Created UDP socket bound to port {}", this.port);
 } catch (SocketException e) {
   logger.error("Error creating socket with port " + this.port 
     + " Will use the next availabel port.", e);
   this.port = SocketUtils.findAvailableUdpPort();
   logger.info("Using alternate port {}", this.port);
   try {
    socket = new DatagramSocket(this.port);
    logger.info("Created UDP socket bound to port {}", this.port);
   } catch (SocketException e2) {
    logger.error("Error creating socket with port " + this.port, e);
   }
 }
}